The slim models are great and reliable. Much more so than the PS2 flat. Has a built in network adapter so it;s just plug and play online. I bought mine brand new becuase I wanted the one year warranty and I suggest you do the same.
$95 bucks is a good deal for a system but you don't know what kind of hell it could have been through. $25 more and you can have a brand new console. Yeah, Sony dropped the PS2 price.
EDIT: I still suggest the slimline over fat. It's all in reliability. The slime will last longer, top loader is better than disk drive. It's smaller and more practical. I thought you could get a hdd for a slim.